Jurassic Brachiopods Research Articles

Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event

ABSTRACT An upper Pliensbachian–Aalenian brachiopod succession is reported from Ponor Mountain, Western Balkan Mountains, Bulgaria. This includes nine species (6 rhynchonellides and 3 terebratulides) from eight genera. A new genus Bulgariarhynchia and two new species, Bulgariarhynchia ponorensis and Capillirhynchia brezenensis, are formally described. A single species Homoeorhynchia ? aff. prona was found in the upper Pliensbachian. Most of the brachiopods derived from the Toarcian–Aalenian interval, and comprise: Pseudogibbirhynchia jurensis, Rhynchonelloidea angulata, Globirhynchia subobsoleta, Sphaeroidothyris uretae, Lobothyris? hispanica, and Telothyris jauberti. The brachiopod assemblages were dated using coeval ammonite biostratigraphy. Both ammonites and brachiopods display clear northwest European affinities. The new brachiopod taxa are considered autochthonous for the Balkan Mountains. Three biofacies (BF2, BF3 and BF5) were recognised and implied alternating suboxic to anoxic bottom water conditions. A few geochemical proxies are indicative of the early Toarcian Oceanic Anoxic Event (T-OAE) in the stratigraphic column. The main T-OAE pulse was fixed at the coeval positive δ13C and negative δ18O excursions, as well as increases in Hg/TOC ratios and redox-sensitive elements. The late Pliensbachian–earliest Toarcian time span was found to be the most hostile for the brachiopods. Above it, brachiopods lived in less stagnant environments.urn:lsid:zoobank.org:pub:22EF76B7-6A4B-4E54-A5BC-38C87125253E

Irish Jurassic brachiopods

A survey of brachiopod specimens recovered from the Jurassic of Ireland, and now preserved in the collections of National Museums Northern Ireland (Belfast) and National Museum of Ireland (Dublin), reveals a total of 23 species comprising 12 rhynchonellides, 6 terebratulides, 3 spiriferinides and 2 lingulides. The identity of some taxa remains uncertain, even to generic level, due to difficulties associated with identification from external morphology alone. Most specimens are from the Lower Jurassic, Hettangian to Upper Pliensbachian, of the Lough Neagh-Larne and Foyle-Rathlin basins in Northern Ireland, but the ultimate source of six Upper Pliensbachian species is unclear as they occur only in glacial erratics that may have been transported to north Antrim from the Hebrides Basin of western Scotland. Three species, all rhynchonellides, are recorded from Lower Pliensbachian strata intercepted in a borehole just off the coast of south Dublin. The Irish fauna overall is comparable with that encountered in similar mudstone-dominated facies in Britain, but these records are of interest in providing an extension of their geographic range further west. Small perforations encountered in two examples of Squamirhynchia from the Raricostatum Zone (Upper Sinemurian) may represent the earliest known examples of gastropod predation on Mesozoic brachiopods.

Irish Jurassic Brachiopods

A survey of brachiopod specimens recovered from the Jurassic of Ireland, and now preserved in the collections of National Museums Northern Ireland (Belfast) and National Museum of Ireland (Dublin), reveals a total of 23 species comprising 12 rhynchonellides, 6 terebratulides, 3 spiriferinides and 2 lingulides. The identity of some taxa remains uncertain, even to generic level, due to difficulties associated with identification from external morphology alone. Most specimens are from the Lower Jurassic, Hettangian to Upper Pliensbachian, of the Lough Neagh-Larne and Foyle-Rathlin basins in Northern Ireland, but the ultimate source of six Upper Pliensbachian species is unclear as they occur only in glacial erratics that may have been transported to north Antrim from the Hebrides Basin of western Scotland. Three species, all rhynchonellides, are recorded from Lower Pliensbachian strata intercepted in a borehole just off the coast of south Dublin. The Irish fauna overall is comparable with that encountered in similar mudstone-dominated facies in Britain, but these records are of interest in providing an extension of their geographic range further west. Small perforations encountered in two examples of Squamirhynchia from the Raricostatum Zone (Upper Sinemurian) may represent the earliest known examples of gastropod predation on Mesozoic brachiopods.

New brachiopod family Arzonellinidae (Terebratulida) from the Early Jurassic (Sinemurian) of Montenegro, southern Europe, Mediterranean Province

ABSTRACT The systematic position of the Early Jurassic brachiopod genus Arzonellina (Sulser) based on new material from Montenegro assigned to Arzonellina stachei (Bittner) and the type species Arzonellina exotica (Sulser), known from southern Switzerland, are discussed. Based on the unusual internal characters, hitherto unknown in detail, the new family Arzonellinidae is erected within the order Terebratulida. An emended diagnosis for the genus Arzonellina is given. The external and internal characters of Arzonellina stachei (Bittner) are described; the specimens came from talus blocks of white recrystallised limestone (rudstones) from Smokovac, southern Montenegro. Arzonellina was originally described from Arzo in the Southern Swiss Alps; the Dinaric Carbonate Platform of Montenegro can now be added to its palaeobiogeographic distribution, with both occurrences located on the Apulian microplate. Associated fauna at both Arzo and Smokovac point to a Sinemurian age for Arzonellina.

First steps in reconstructing Early Jurassic sea water temperatures in the Andean Basin of northern Chile based on stable isotope analyses of oyster and brachiopod shells

The stable isotope (δ13C, δ18O) composition of a collection of Lower Jurassic brachiopods and oysters from the Andean Basin of northern Chile was analyzed. The results allow the first reconstruction of absolute water temperatures for several ammonite zones in the Lower Jurassic of South America. The temperature record starts with comparatively high values in the Late Sinemurian (average: 27.0 °C; Raricostatum Zone). Just before the Sinemurian–Pliensbachian transition, temperatures dropped to an average of 24.3 °C. The lowest temperature value in the dataset was recorded for a brachiopod shell of the latest Pliensbachian Spinatum Zone (19.6 °C). No data are available for the Early Toarcian, but results for the late Toarcian show again comparatively warm conditions (average: 24.4 °C; Thouarsense–Levesquei zones). Even though more material and analyses are necessary to corroborate the recorded temperatures, the present dataset seems to indicate the global nature of the Late Pliensbachian Cooling Event. In contrast, the global warming during the Toarcian Oceanic Anoxic Event has not been recorded due to a lack of Early Toarcian material. The δ13C record of brachiopods and oysters documents a gradual increase in values representing background conditions. Oyster shells were used for high-resolution stable isotope analyses and show seasonal temperature fluctuations over a period of around 3 years in the life time of the bivalves. If explained only by temperatures, the δ18O values point to a minimum estimate for the seasonality in the late Toarcian of slightly more than 3 °C.

Callovian (Middle Jurassic) terebratulide brachiopods from the Jordan Valley (northwestern Jordan)

ABSTRACT Middle Jurassic terebratulide brachiopods from the Jordan Valley are herein revised and new taxa are added to the previous faunal list. The Callovian rocks (Mughanniyya Formation) of the Tel el Dhahab section has allowed recognising two new terebratulide taxa: Kutchithyris simoni sp. nov. and Trigonithyris wilsoni sp. nov, which are formally described herein. Additionally, three terebratulide species: Bihenithyris barringtoni, Ptyctothyris daghaniensis, and Sphriganaria cardioides are reported for the first time from Jordan, all of them recorded together Bihenithyris weiri, a more widespread taxa in the Ethiopian Province. The Callovian Mughanniyya Formation of northwest Jordan is dominated by highly fossiliferous limestone beds intercalated with marlstones deposited on a low angle carbonate ramp in a shallow protected, inner shelf setting. Brachiopods of the Jordanian Mughanniyya Formation can be correlated with the Callovian brachiopod faunas of the Aroussiah Formation in Sinai and the Zohar and Matmor formations in southern Israel. The high degree of endemism of the terebratulide brachiopods under study here is yet another confirmation of the pronounced Middle Jurassic endemism along the southern Tethyan margin of the Ethiopian Province.

Middle Jurassic terebratulide brachiopods from the Jordan Valley (northwestern Jordan)

ABSTRACT The Middle Jurassic terebratulide brachiopods from the Jordan Valley, northwestern Jordan, are herein revised and systematically described and new taxa are added to the faunal list. A new genus and species Jordanithyris ardainensis gen. et sp. nov., is introduced from the upper Bathonian (Hamam Formation) and lower Callovian (Mughanniyya Formation) of the Arda section. In the upper Bathonian Hamam Formation (consisting of limestone, dolomite, alternating sandstone, and marlstone beds), Ptyctothyris quillyensis occurs. The assemblage Arabatia bihinensis, Ectyphoria sinaiensis, Ptyctothyris quillyensis, Dorsoplicathyris dorsoplicata, and Tubithyris jurayfahiensis is recorded in the lower Callovian limestone beds with marlstone interbeds of the Mughanniyya Formation. Brachiopods of the Jordanian Hamam and Mughanniyya formations can be correlated with the fauna of the Aroussiah Formation in Sinai and the Zohar and Matmor formations in southern Israel. The sedimentary environment is interpreted as the protected shallow inner shelf, and nutrient rich habitat resulting in high faunal diversity. The high degree of endemism of this fauna is yet another confirmation of the representative pronounced Middle Jurassic endemism along the southern Tethyan margin of the Ethiopian Province.

EARLY JURASSIC TEREBRATULIDE BRACHIOPODS FROM ZEALANDIA

Terebratulides, a minor group in New Zealand and New Caledonian Triassic faunas, become second in prominence only to rhynchonellides in the Jurassic. In this study, a total of seven genera and twelve species are recognised and eight new species are described. Lobothyris simesi n. sp. is present throughout the Sinemurian to middle Toarcian. Loboidothyris fordycei n. sp. is common in the late Sinemurian to Pliensbachian of the Hokonui Hills, and a few specimens are recorded from scattered Pliensbachian-Toarcian localities elsewhere. Zeilleria spiculata MacFarlan and Campbell is found in a narrow zone along the Triassic-Jurassic boundary in the Hokonui Hills. Z. terezowae n. sp. is found throughout most of the Early Jurassic, while Z. recessa n. sp. and Z. sacciformis n. sp. have more restricted ranges. The Sinemurian Aulacothyris stevensi n. sp. is known from the Hokonui Hills, and the coast north of Marokopa. Two further forms of Aulacothyris are present. Linguithyris agerorum Mancenido was described from Port Waikato, and is here recorded from New Caledonia. Tegulithyris? plencnerae n. sp. is known from the Sinemurian to Toarcian of Kawhia, and Rugithyris hasibuani n. sp. from the Awakino area. Lobothyris, Aulacothyris and Zeilleria are cosmopolitan and widely distributed. Loboidothyris is also cosmopolitan, but has a Tethyan aspect. Tegulithyris and Rugithyris are Tethyan. Linguithyris is also known from southern Europe, North Africa and western Asia. The highest Early Jurassic brachiopod faunas occur at or just above the Dactylioceras band near Kawhia, which is correlated with the top of the early Toarcian and lies above the Toarcian event in Western Europe.

First evidence of brachiopod diversification after the end-Triassic extinction from the pre-Pliensbachian Internal Subbetic platform (South-Iberian Paleomargin)

Lower Jurassic brachiopods are widely known in the External Betic Zone. Their occurrence was so far virtually restricted to the easternmost Subbetic Zone where they underwent a diversity burst and radiation event during the late Sinemurian–early Pliensbachian interval, leading to a bloom in brachiopod diversity from the early Pliensbachian onwards. Taxonomical and paleobiogeographical analyses performed in a newly recorded assemblage from the most offshore areas of the Subbetic Basin (Granada province, Spain) reveals that this diversification event occurred earlier than expected hitherto, probably in the Turneri–Obtusum chronozones, as similarly observed in the most intra-Tethyan basins such as the Northern Calcareous Alps and Transdanubian Ranges, illustrating the recovery of the background conditions for the establishment of diversified brachiopod communities after the end-Triassic extinction event. A new rhynchonellide species, Alebusirhynchia vorosi nov. sp., is formally described among the ten different taxa recorded for the first time in this area. The Mediterranean paleobiogeographical affinities revealed by the brachiopod assemblage emphasizes that the onset of the Mediterranean/Euro-Boreal bioprovinciality and the initial brachiopod diversification in the pre-Pliensbachian Internal Subbetic platform took place earlier in the Sinemurian as well, following the Euro-Boreal monotypic record previously reported in this region.

Did plate tectonics control the generic diversity of Jurassic brachiopods? One point of view

Abstract Possible plate tectonic controls on faunal diversity dynamics have been discussed in the geological literature for around 50 years. The new model of plate tectonic processes is here linked to Jurassic generic diversity (simple α-diversity) of brachiopods. This comparison offers three observations, four hypotheses and three unresolved issues. Most importantly, changes in the global plate root mean square speed coincided with brachiopod diversity dynamics, which can be explained hypothetically by either environmental disturbance triggered by more active plate motion or activity of any process (such as eustasy) tied to plate tectonic mechanisms and with an impact on marine benthic communities. It is also established that global generic diversity dynamics of brachiopods during the Jurassic coincided with the regional picture as established for the Northern Caucasus and the Swiss Jura Alps; this coincidence is difficult to explain with regard to plate tectonics. These and other speculative considerations do not clarify the role of the plate tectonic factor in Jurassic generic diversity dynamics of brachiopods, and, thus, they indicate important issues for further research.

First supplement to the catalogue of invertebrate and vertebrate palaeontological type specimens of the Hungarian Natural History Museum: 2008–2018

A comprehensive palaeontological type catalogue of the Hungarian Natural History Museum (Budapest) was published in 2008. In the following ten years several new type specimens were deposited in the collection, both invertebrates and vertebrates, from microscopic radiolarians to large dinosaur bone remains. Triassic radiolarians and ammonoids, Jurassic brachiopods, Cenozoic molluscs, and Cretaceous vertebrates represent the most dynamically growing parts of the type collection. This supplement to the original catalogue contains the data of 175 species and subspecies, of which 148 are new taxa for the type catalogue. Among them 125 are represented by holotypes, and an additional 199 inventory lots of their paratypes; 23 new taxa are represented only by paratypes, in an additional 74 inventory lots. The vast majority of these taxa were recently described (between 2008 and 2018), although a few of them are previously established taxa with type material that was newly recognized to exist in our collection. This supplement also contains the data of four recently designated neotypes, as well as 16 rediscovered old type specimens which were reported as missing in the 2008 catalogue. We also include the known revisions and illustration of 14 previously established species and subspecies (in three cases with lectotype designation). At the end of 2018, the invertebrate and vertebrate palaeontological collection of the Hungarian Natural History Museum holds more than 2500 inventory lots of different type specimens, including name-bearing types of 1056 nominal species and subspecies.

A new occurrence of the Early Jurassic brachiopod Anarhynchia from the Canadian Cordillera confirms its membership in chemosynthesis-based ecosystems

Cold seeps, where seepage of hydrocarbon-rich fluids occurs in the sea floor, are sites that harbor highly specialized ecosystems associated with distinctive carbonate sediments. Although their Mesozoic record is scarce and patchy, it commonly includes dimerelloid rhynchonellide brachiopods. Here we report a monospecific assemblage of Anarhynchia from a limestone boulder of early Pliensbachian (Early Jurassic) age in the Inklin Formation of the Whitehorse Trough in the Stikine terrane, from a locality at Atlin Lake in northern British Columbia. Specimens are among the largest known Mesozoic brachiopods, up to 9 cm in length, and described here as Anarhynchia smithi n. sp. Early precipitated carbonate cement phases of the limestone have carbon isotopic composition highly depleted in 13C, indicative of the influence of microbial oxidation of methane derived from a cold seep. Carbonate petrography of the banded-fibrous cement and other characteristic components supports this paleoenvironmental inference. Volcanogenic detrital grains in the matrix are indistinguishable from those in the sandstone layers in the siliciclastic sequence, suggesting that the seep carbonate is broadly coeval with the enclosing conglomerate. The new record extends the geographic range and species-level diversity of the genus, but supports its endemism to the East Pacific and membership in chemosynthesis-based ecosystems. The distribution of three distinct but congeneric species suggests that allopatric speciation occurred at separate sites along the active margin of western North America and Anarhynchia was restricted to seep and vent habitats in the Early Jurassic.

Lower Jurassic brachiopods from the Ibero-Levantine Sector (Iberian Range): Faunal turnovers and critical bioevents

Brachiopod fauna from the peri-Iberian platform system is well-known in the Late Pliensbachian-Toarcian interval. However, the diversity dynamics and the stratigraphical distribution of this group in the Ibero-Levantine Sector of the Iberian Range require more accurate analysis due to the patchy distribution of the outcrops. The abovementioned timespan involved a period of changes in long-term environmental conditions which led to a severe extinction and critical turnovers on the brachiopod fauna (ETMEE). The Ibero-Levantine sector has notable palaeobiogeographical significance as it represents the south-easternmost outcrops of the Iberian Range connecting with the Betic Domain positioned in the South-Iberian Palaeomargin. In this region, the brachiopod fauna has been arranged into six assemblages, showing a discontinuous stratigraphic distribution since its diversity dynamics is markedly conditioned by the extinction phases linked to the ETMEE: Ass. 1, recorded in the Spinatum-lower Tenuicostatum chronozones; Ass. 2, mainly recorded in the Tenuicostatum chronozone; Ass. 3, typifying the lower Serpentinum chronozone; Ass. 4, documented in the Serpentinum-lowermost Bifrons chronozones; Ass. 5, recorded in the Bifrons-Variabilis chronozones, and Ass. 6, distinctive of the Pseudoradiosa-Aalensis chronozones. The faunal succession shows strong affinities with the Euro-Boreal province, what rules out the transitional or even Mediterranean palaeogeographical affinity previously attributed to the southernmost part of this area. Amidst the main brachiopod-based bioevents must be considered the predominance of the genus Lobothyris in the pre-ETMEE assemblages, the conspicuous record of Liospiriferina? undulata, distinctive taxon of the north-African margin and, especially, the first record in the Iberian Peninsula of thecideid marker beds prior to the ETMEE. After the opportunistic strategy conducted by Soaresirhynchia bouchardi the distribution of the post-ETMEE brachiopod assemblages is markedly influenced by the depositional sequences, entailing premature turnovers and involving the earlier record of homeomorphic morphotypes of younger terebratulides and rhynchonellides.

Middle and Late Jurassic terebratulides from New Zealand

Terebratulide brachiopods are found throughout the New Zealand Mesozoic, and by the Jurassic are second only to rhynchonellides in abundance and diversity. Only two species have been described from the Late Jurassic, Kutchithyris hendersoniMarwick, 1953 and Holcothyris (?) kaiwaraensisCampbell, 1965. In this study, one new genus and 14 new species are described, and three additional forms placed in open nomenclature.Nearly all the material comes from the Murihiku Terrane on the west coast of the North Island south of Auckland, and most from a small number of shellbeds with diverse faunas. Two key localities for Middle Jurassic (Bajocian–Bathonian) brachiopods are Opuatia Cliff at Port Waikato, and a quarry in the Marokopa Valley. Two species of fairly large terebratulide, Loboidothyris waitomoensis n. sp. and L. grantmackiei n. sp. are tentatively assigned to the genus Loboidothyris. A further species which may also belong to this genus, L. awakinoensis n. sp. is found in the Awakino Valley to the south. Two species of Zeilleria, Z. opuatiaensis n. sp. and Z. waiohipaensis n. sp. and one of Aulacothyris, A. waikatoensis n. sp. are also recognised. A new species of Kutchithyris, K. marokopaensis n. sp., less strongly folded than K. hendersoni, is also present.Captain King's Shellbed is a metre-thick Oxfordian shellbed that can be traced from Kawhia to the Awakino Valley. It has a rich and diverse fauna in which terebratulides are prominent. Kutchithyris hendersoni is the most abundant, followed by Crispithyris nauarchus n. gen. n. sp. The fauna also includes the same two species of Zeilleria as in the Middle Jurassic, and the costellate terebratulide Terebratulina leeae n. sp.Brachiopods are much less common in the later part of the Jurassic (Kimmeridgian and Tithonian). A further species of Kutchithyris, K. challinori n. sp., a second species of Terebratulina, T. putiensis n. sp. and one of Zeilleria (Z. sp.) are present. A rare form is the small subcircular Disculina mancenidoi n. sp. Holcothyris kaiwaraensis is known only from the Late Jurassic Pahau Terrane of North Canterbury, but a second species of Holcothyris, H. campbelli n. sp. is present in the Late Oxfordian and Kimmeridgian of the Kawhia area.Aulacothyris, Terebratulina, and Zeilleria are cosmopolitan. Kutchithyris and Holcothyris are Tethyan. Loboidothyris is more widely distributed but generally Tethyan. Disculina is described from Southern England and France, but has since been recognised in the Caucasus and Japan, and may also have a Tethyan distribution.

Early Jurassic (Pliensbachian) brachiopod biogeography in the western Tethys: The Euro-Boreal and Mediterranean faunal provinces revised

The Pliensbachian brachiopod biogeography of the western Tethyan region and the Euro-Boreal vs. Mediterranean faunal provinciality is evaluated. The data base was developed from improved and mostly revised taxonomical data of 25 Pliensbachian brachiopod localities selected from Europe and North Africa. The revised list and presence-absence data of 405 Pliensbachian brachiopod species formed the taxonomic units of the numerical analysis based on similarity coefficients. Cluster analysis (hCA) carried out from the Jaccard and Raup-Crick coefficient data showed clear dichotomy between the Euro-Boreal and Mediterranean brachiopod biochores. Principal coordinates (PCO) technique and non-metric multi-dimensional scaling (NMDS), complemented with the minimal spanning trees, resulted in similar grouping of the Pliensbachian brachiopod faunas. In de-trended correspondence analysis (DCA), besides the clearly separated Euro-Boreal and Intra-Mediterranean units, the Peri-Mediterranean assemblage formed a discrete scatter between the two major biochores. The three Algerian faunas (Ouar, Trar, Ksou) appear in a somewhat marginal position within the Euro-Boreal province. The above Pliensbachian brachiopod biochores reveal very high degree of endemicity, probably related to the limited dispersal potential of brachiopods. From the complete data set distinctive Euro-Boreal and Mediterranean species, ten from both provinces, were selected. Ribbed spiriferinid morphotypes are frequent among the distinctive Euro-Boreal species, whereas, besides smooth spiriferinids, some rhynchonellid and terebratulid morphotypes with expanded anterior margins are common among the distinctive Mediterranean species. In the Early Jurassic Tethyan palaeogeography, the marked dichotomy between the Euro-Boreal and Mediterranean provinces is interpreted in terms of deep-sea/oceanic barriers, which isolated the intra-Tethyan microcontinent from the European and African shelf regions. Geographical position and local environmental factors caused the differentiation of the Peri-Mediterranean subprovince along the north-western margin of the microcontinent. This palaeobiogeographical unit formed an interface between the Intra-Mediterranean and the Euro-Boreal biochores.

Similarity of Early and Middle Jurassic brachiopods between the Danubian and Getic tectonic units of eastern Serbia

Rich brachiopod assemblages are known from the Lower and Middle Jurassic deposits of the Danubian and Getic tectonic units (eastern Serbia). A quantitative assessment of the relevant palaeontological data can shed light on the relationship of these units in the palaeospace. In the present study, the brachiopod assemblages from the Danubian and Getic tectonic units are compared with similarity indices (the Jaccard similarity of species, genera, families, and superfamilies, and the Czekanowski and Gower similarity of the genus–species, family–species, and superfamily-species diversity structures). This analysis is applied to five geological time slices when brachiopods flourished regionally, namely the Early Pliensbachian, the Late Bajocian, the Early Bathonian, the Middle Bathonian, and the Late Bathonian. Generally, the values of the indices imply moderate similarity. The similarity was significantly lower in the Middle Jurassic relatively to the Early Jurassic. The similarity of the Early Pliensbachian brachiopods of the Danubian and Getic tectonic units was significant relatively to the similarity between some European regions. The documented decrease in the similarity through the geological time can be explained by the increase in the global palaeobiogeographical differentiation in the Middle Jurassic.

Diversity dynamics of Early and Middle Jurassic brachiopods in the Getic and Danubian tectonic units of eastern Serbia: Regional versus global patterns

Quantitative assessment of regional diversity patterns reveals trajectories of faunal development on the basin scale and helps to understand its dependence on palaeoenvironmental changes, global-scale biotic evolution, and major events in the history of the Earth. A total of 86 species, 50 genera, 18 families, and 9 superfamilies of Early and Middle Jurassic brachiopods are established in the Getic and Danubian tectonic units of eastern Serbia. Compilation of their stratigraphic ranges allows analysis of their total diversity, number of appearances and disappearances, and turnovers. In both units, brachiopods radiated rapidly in the Early Pliensbachian. Then, their diversity declined, and these fossils disappeared. A new radiation took place in the Late Bajocian, and brachiopods remained diverse until the end of the Bathonian. They disappeared before the Callovian in the Getic Unit and in the Early Callovian in the Danubian Unit. The Early Pliensbachian radiation was significantly stronger than the Late Bajocian at the level of species; the strength of these radiations was more or less comparable at higher taxonomic levels. The strength of turnovers among brachiopods differed through geological time. The composition of the Middle Jurassic brachiopod assemblages was more or less stable. Regional shoreline shifts, basin depth changes, palaeobiogeographical changes, and plate tectonic re-organizations were possible controls on regional patterns of brachiopod diversity dynamics. However, the latter also reflects some diversity patterns documented globally and in some other regions (the Bakony Mountains, the Swiss Jura Mountains, and the Northern Caucasus).

Bajocian-Early Bathonian (Jurassic) brachiopods from the Subbetic domain (Betic Cordillera, SE Spain): Taxonomy and palaeobiogeographic implications

Bajocian-Early Bathonian (Jurassic) brachiopods from the Subbetic domain (Betic Cordillera, SE Spain): Taxonomy and palaeobiogeographic implications

Early Jurassic (latest Toarcian) brachiopods from the northeastern margin of the Western Tethys (Central Iran) and their paleobiogeographical significance

Brachiopod fauna from central Iran, recorded in the upper part of the Shemshak Group and attributed to the upper Toarcian (Pseudoradiosa-Aalensis zones), are reported for the first time in Iran. The assemblage recognized includes six different taxa: Homoeorhynchia sepahanensis nov. sp., formally described in this paper, Globirhynchia subobsoleta, Pseudogibbirhynchia sp., Tetrarhynchiidae sp. indet., Monsardithyris? aff. haresfieldensis, and Zeilleria cf. leckenbyi. Analysis of faunal affinities with other paleobiogeographical regions shows a free connection of the central Iranian brachiopod fauna and wide areas of the northern shelf margin of the Tethys Ocean. This is due to an apparent disruption of bioprovinciality inferred for the late Toarcian-earliest Aalenian, congruent with a connection through the northern seaway across the peri-Laurasian epicontinental platforms.

A Jurassic (Bathonian-Callovian) Daghanirhynchia brachiopod fauna from Jordan

A Jurassic (Bathonian-Callovian) brachiopod fauna from Jordan consists of seven rhynchonellid species all belonging to the genus Daghanirhynchia of which two are new: Daghanirhynchia rawyaensis and D. jordanica. Emended diagnoses are given for Daghanirhynchia daghaniensis and D. macfadyeni. Additional taxa described include Daghanirhynchia angulocostata, D. susanae and D. triangulata. Threedimensional reconstructions illustrate the internal morphology of the articulated shells for the first time in this genus. The material studied herein was collected from Wadi Zarqa in northwestern Jordan, almost due north of the Dead Sea, and to the east of the Rift Valley. Most species seem to be geographically restricted within the Jurassic Ethiopian Province, however specimens from Somalia and Ethiopia are larger in size than in other parts of the Province and shell size increases in stratigraphically younger specimens. The occurrence of Daghanirhynchia in India is the only appearance of the genus outside the Ethiopian Province.